(1) Field of the Invention
This disclosure relates to an n-type thermoelectric conversion material of a (Zr,Hf)3Ni3Sb4-based thermoelectric conversion material for use in thermoelectric generation or thermoelectric cooling.
(2) Description of Related Art
Thermoelectric generation is a technique of directly converting thermal energy into electric energy by using a Seebeck effect, that is, a thermal electromotive force generated between the ends of a material in proportion to a temperature difference when the temperature difference is set between the ends of the material. This technique is put into practical use in part as a remote-area electric power source, an outer-space electric power source, a military-use electric power source, etc. Thermoelectric cooling is a technique that uses a Peltier effect, that is, a phenomenon that electrons carried by a current move heat. For example, the thermoelectric cooling is a technique of, when two materials each including electric conduction carriers having a polarity different from that of electric conduction carriers of the other material are connected in thermally parallel and in electrically series and a current is caused to flow through the materials, absorbing heat in the connection portion therebetween by using the fact that the difference in the polarity between the electric conduction carriers (carriers) reflects on the difference in the direction of a heat flow.
A (Zr,Hf)3Ni3Sb4-based n-type thermoelectric conversion material is described in J. R. Salvador, X. Shi, J. Yang, and H. Wang, “Synthesis and transport properties of M3Ni3Sb4 (M=Zr and Hf): An intermetallic semiconductor”, Physical Review B 77, 235217, Jun. 27, 2008 (called as Non-Patent Literature 1).